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[IDD #GTV-595062]: NEXRAD data

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  • Subject: [IDD #GTV-595062]: NEXRAD data
  • Date: Tue, 06 Apr 2010 12:06:50 -0600
Hi Russ,

re:
> SSEC is not getting NEXRAD radar images as off about 12GMT this
> morning. Is there something that happened early on this morning??

I assume that you mean the Nexrad Level III images from NOAAPort, correct?

I just looked at the data volumes on the SSEC NOAAPort ingest machines,
and their NEXRAD data volumes look very low in comparison to what
we are seeing:

dvb1.ssec.wisc.edu
http://www.unidata.ucar.edu/cgi-bin/rtstats/iddstats_vol_nc?NNEXRAD+dvb1.ssec.wisc.edu

dvb2.ssec.wisc.edu
http://www.unidata.ucar.edu/cgi-bin/rtstats/iddstats_vol_nc?NNEXRAD+dvb2.ssec.wisc.edu

jackie.unidata.ucar.edu
http://www.unidata.ucar.edu/cgi-bin/rtstats/iddstats_vol_nc?NEXRAD3+jackie.unidata.ucar.edu

I would assume, therefore, that there is a problem with the NOAAPort signal
at SSEC.  Please tell whoever is now in charge of those systems that they
should reset the Novra S75 unit.  This is typically done using the S75_TEST
routine run from the 'ldm' account on the ingest machine.  If you actually
have two Novra's (one for each machine, not a split/replicated feed from one
Novra going to both ingest machines), then they both need to be reset.

My hunch behind my recommendation to reset is that the S75(s) have drifted off
of the correct frequency of 1193.5.  Or, the viterbi bit error rate is
"large" (greater than about 10**-6).  I just checked our Novra and saw
that the viterbi bit error rate was 2.4600e-05, which is very high for
us.  I immediately reset the device (through the S75_TEST reset action),
and it is now down to where it should be: 0.0000e+00.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: GTV-595062
Department: Support IDD
Priority: Normal
Status: Closed